Feed-water-supply apparatus for steam-generators



T. CLARKSON. FEED WATER SUPPLY APPARATUS FOR STEAM GENERATORS.

APPLICATION FILED SEPTA, 1918. 1,350,988.

2 SHEETSSHEET I.

fmfz W Patented Aug. 24, 1920.-

T. CLARKSON. FEED WATER SUPPLY APPARATUS FOR STEAM GENE RATORS.

APPLICATION FILED SEPT- 4, I918.

Patented Aug. 24, 1920.

2 SHEETS-SHEET 2.

THOMAS CLARKSON, OF CLI-lELlVISFORD, ENGLAND.

FEED-WATER-SUPPLY APPARATUS Specification of Letters Patent.

STEAM- GENERATORS.

Patented An 2%, 1920.

Application filed September 4, 1918. Serial No. 252,620.

To all whom it may concern:

Be it known that I, TnoMAs CLARKSON, subject of the King of England, residing at Cliehnsford Essex, in England, have invented certain new and useful Improvements in FeedlVater Supply Apparatus for Steam-Generators, of which the following is a specification.

This invention relates to feed water supply apparatus for steam generators more particularly the mechanism by means of which the movements of a float regulator can be utilized to control the water delivered by the feed pump.

i rccording to this invention the suction valve of the pump is adapted to be lifted and held off its seat, so as to prevent delivery of the water drawn into the pump, by a lever mounted on a shaft which is rocked by the movements of a float which result from variations in the level of the water in the generator, while the rockshaft has imparted to itconstant reciprocating movement in the direction of its axis whereby the shaft is kept free so that the application of only a small force is necessary to rock it. One end of the rockshaft is carried by a st-u'liing box through which it passes into a chamber whence the water is drawn past the suction valve and the reciprocating motion of the rockshaft, obviates any tendency for this stuffing box to offer such resistance to the rotation of the shaft as will prevent the float movements being imparted through the shaft to the suction valve of the pump. On the end of the rockshaft within the pump chamher is a lever which can so-act on the suction valve as to lift and support this valve off its seat and retain it so until the water level in the generator has fallen suiliciently to cause the float to move and permit the suction valve again to seat itself. While this valve is lifted the water drawn in by the pump is merely forced back again to the tank and is not delivered to the generator. The necessary reciprocating movements may be imparted to the rockshaft in various ways but conveniently by a lever which bears against the end of the rockshaft, hardened bearing surfaces between these parts being provided. This lever is moved by means of suitable mechanism from some convenient source of power so that the shaft is constantly pushed by the lever in one direction. The return movement is brought about preferably by the action of a spring. Various lever and link connections may be employed between the rockshaft and the float spindle.

The accompanying drawings illustrate by way of example one method of putting the invention into n'actice. In these drawings.

Figure 1 is a vertical sectional elevation of the pump and shaft by means of which the valve is lifted off its seat. The parts at the left hand end of the figure are shown in plan for the sake of clearness.

Fig. 2 is a vertical section through the pump on the line 22 of Fig. 1 looking in the direction of the arrows.

Fig. 3 is a somewhat diagrammatic perspective view showing the disposition of the regulating mechanism and the relation ship between the pump control device and the float which actuates it.

Like letters indicate like parts throughout the drawings.

In the float construction the spindle A on which the float B is mounted passes through the wall of a casing C which incloses the float and is in communication with the steam generator D so that water can freely enter the casing from the generator. The float spindle A has imparted to it a constant reciprocating movement in the direction of its axis so as to maintain the bearings of the spindle free and permit the float B to move freely under the influence of the varying water level. This reciprocating movement may conveni ntly be derived from a suitably disposed rock shaft E provided with two lever arms E and E and the shaft is rocked by suitable mechanism connected to the arm E. The arm E is connected by a link with one arm 3 of a two armed lever pivoted at F on some fixed part. On theencL of the other arm F of this lever is a member F which abuts against the ends of the float spindle A. As will be seen by means of this mechanism when the shaft E is rocked the lever l will be oscillated ant. the spindle A will be moved thereby either in both directions by means of a bridle gear or the lever may move the spindle in one direction only the return movement being effected conveniently by means of a spring not shown in the drawings. The general arrangement of this mechanism is illustrated in Fig. 3.

The feed pump employed may be of any known construction but conveniently as shown in l the delivery va ve G is mounted in the pump casing ll opposite to the suction or inlet valve J. There is ar ranged beneath the suction valve 5 a spindle J which can slide in a guide member G" formed in the pump casing. The upper end J of the spindle J loosely engages the underside of the valve J while the lower the end L of a rockshaft which extends through the wall of the pump chamber G into which chamber the water enters on its way to the suction valve J. hen the shaft L is turned it will cause the lever K to so act on the spindle J as to slide this spindle in the guide G and lift the valve J off its seat sufficiently to insure that water drawn in by one stroke of the Jump will on the return stroke be delivered back again into the supply tank through the ports which would normally be covered by the suction valveJ. V

A stu'liing box G of suitable construction is'provided where the rockshaft L passes into the pump chamber G The shaft L is conveniently formed in two lengths the second-part L being connected to the part L by a flexible ring L or in some other manner which will allow of slight flexure of the shaft in order to obviate the necessity for strict alinement of the bearings in which the shaft is mounted. One of these bearings in constituted by thestuffing box G while the other bearing M is conveniently arranged at the opposite end of the shaft length L. There may also be an intermediate bearing not shown in Fig. 1. The joint L between the two parts L and L of the shaft may be formed in any convenient manner but preferably as shown there 1s a boss L at the end of the shaft acts on the shaft L L as to tend to draw its end through the stuffing box G out of the pump chamber G The end L* of the shaft part L which is opposite to the coupling L and is carried in the bearing M lies against one arm ()Iof a bell crank lever pivoted at some fixed part at O. The end of the shaft and a part of the lever with which it is in contact are hardened ora steel ball is disposed between these parts or the construction is otherwise so as to provide where these parts are in contact bearing surfaces adapted to stand wear. The other arm of the bell crank lever is connected by a link 0 with the lever arm E on the rockshaft E. Thus when this shaft is turned in the manner described by power applied to the lever arm E the bell crank lever O 0 will be moved and the shaft L Lwill be forced in the direction of its axis against the action of the coiled spring N which returns the shaft after the lever O has completed the movement in one direction. A constant reciprocating movement is thus imparted to the shaft L L which is in this way kept free in the stuffing box G so that the float as it moves can without undue resistance cause the shaft-L L to be turned about its axis. As is apparent the reciprocation of the float spindle A is effected simultaneously with the reciprocation-of the shaft L L.

The movements of the float B are communicated to theshaft L L by means of a lever A on the float spindle A which is connected by a link A to a lever L mounted on the part L of the shaft whiehcontrols the pump valve. The connections be tween these levers and the link are such as to allow for the reciprocating movements which are imparted respectively to the float spindle A and to the shaft L.

For the sake of clearness in Fig. 1 the left hand part of that figure as already indicated is in plan so as to show the positions of the levers L and O O and the correct relationship of these levers with the other parts of the mechanism is apparent from Fig. 3. in the latter figure the pump casing is omitted and the pump suction valve J is diagrammatically illustrated with its spindle J in relation to the lever K. The spring N and other parts are also omitted for the sake of clearness. V

The details of construction may be varied in accordance with requirements and the type of generator, float and pump with which the above described mechanism is employed.

lVhat I claim as my invention'and desire to secure by Letters Patent is 1. In apparatus for regulating the feed water supply of steam generators the combination of a steam generator, a feed water pump, a rockshaft extending through the wall of the pump casing adjacent to the suction valve of the pump, a lever mounted on the rockshaft within the pump casing and adapted to lift the suction valve off its seat when the shaft is rocked, mechanism to which movement is imparted by variations in the level of the water in the steam gen erator, means by which the movements of this mechanism are communicated to and rock the shaft, mechanism by means 1 of which axial movement is imparted intermittently to the rockshaft in one direction,

and a spring operative to move the rockshaft in the opposite direction as set forth.

2. In apparatus for regulating the feed water supply of steam generators the combination of a steam generator, a feed water pump, a rockshaft extending through the wall of the pump casing adjacent to the suction valve of the pump, a lever mounted on the rockshaft within the casing and adapted to lift the suction valve off its seat when the shaft is rocked, a float disposed so as to be subject to and movable by variations in the level of the Water in the generator, means by which the movements of the float are communicated to and rock the shaft, mechanism by means of which axial movement is imparted intermittently to the rockshaft in one direction, and a .spring operative to move the rockshaft in the opposite direction as set forth.

3. In apparatus for regulating the feed water supply of steam generators the combination of a steam generator, a feed Water pump, a rockshaft extending through the wall of the pump casing adjacent to the suction valve of the pump, a lever mounted on the rockshaft within the casing and adapted to lift the suction valve off its seat when the shaft is rocked mechanism by means of which axial movement is imparted intermittently to the rockshaft in one direction, a spring operative to move the rockshaft in the opposite direction, a chamber in such communication with the steam generator that water from the generator can freely enter and partly fill the chamber, a rotatable spindle which extends through the wall of the chamber, a float mounted on the spindle Within the chamber so that it can rise and fall as a result of variations in the level of the water in the chamber and thereby rotate the spindle, and means by which the rotary movements of the float spindle are communicated to the rockshaft as set forth.

l. In apparatus for regulating the feed water supply of steam generators the combination of a steam generator, a feed water pump, a rockshaft extending through the Wall of the pump casing adjacent to the suction valve of the pump, means for reciproeating this shaft in the direction of its axis, a lever mounted on the rockshaft within the pump casing and adapted to lift the suction valve off its seat when the shaft is rocked, achamber in such communication with the steam generator that water from the generator can freely enter and partly fill the chamber, a rotatable spindle which extends through the wall of the chamber, a float mounted on the spindle within the chamber sothat it can rise and fall as a result of variations in the level of the water in the chamber and thereby rotate the spindle, means by which the rotary movements of the float spindle are communicated to the rockshaft, and means for reciprocating the float spindle in the direction of its axis as set forth.

In testimony whereof I have signed my name to this specification.

THOMAS OLARKSON. 

